Ball-caster



(N0 odel.

RYMPLH, BALL GASTER.

' Patented Apr. 1, 1890.

' UNITED STATES PATENT OFFICE.

' HARTIVELL DALRYMPLE, OF RUTLAND, VERMONT.

BALL-CASTER.

SPECIFICATION forming part of Letters Patent No. 424,467, dated April 1,1890.

Application filed December 2, 1889- Serial No. 332,223. (No model.)

To all whom it may concern:

Be it known that I, HARTWELL A. DAL- RYMPLE, a citizen of the UnitedStates, residing at Rutland,in the county of Butland and State ofVermont, have invented a certain new and useful Improvement in Casters,of which the following is a full, clear, and exact description.

This invention relates to that class of casters in which a ball is used.instead of a wheel or roller.

The object of the invention is to facilitate the production and reducethe cost of such casters. Another object is to reduce the frictionincident to ball-casters, and thus render them more durable and moreeasily operable.

The invention consists of a ball-caster, in

which the sphere is placed in an open frame or socket, constructedsubstantially as hereinafter described and claimed, so that the spherebears upon the frame or socket only at points of contact instead ofhaving any appreciable extent of its surface bearing thereupon, such asthose balls have which are surrounded by a socket of similar shape tothe ball.

In the accompanying drawings, illustrating my invention, in the severalfigures of which like parts are similarly designated, Figure 1 is avertical sectional elevation, on a rather large scale, showing one formof application of the invention. Fig.2 is a perspective View of theframeor socket detached. Fig. 3 is a horizontal section taken in the plane ofline :0 m, Fig. 1. Fig. at is a perspective View of a modification, andFigs. 5 and 6 sectional details showing the caster applied,respectively, to a sewing-machine-table leg and an iron safe. Fig. 7 isa bottom view of the safecaster, the section of Fig. 6 being taken inthe plane of line y 'y of this Fig. 7.

The frame or socket is composed of a faceplate a, in which a rectangularopening I) is.

made, and the edges of this opening are beveled, substantially as shown,so as to remove sharp edges from contact with the sphere c, which sphereworks within the said opening in the said face-plate without contactwith its sides when in use, but having an endwise and also a slightlateral play in the said opening. hen the caster is for use on woodenfurniture and other articles, a cap-plate d is ar ranged upon theface-plate and is arched over the back of the face-plate and over thelength of the opening I) in the said face-plate, so as to confine thesphere and serve as a wearplate and bearing for the sphere. Thiscapplate preferably is a fiat strip of metal bent substantially to theshape shown. It may be united to the face-plate in any suitablemanner-as, for example, by means of lugs or projections made on thecap-plate and extended through openings in the face-plate and riveted onthe outside of the face-plate, substantially as indicated at e e in Fig.1, or it may be separate from the face-plate; or it may have lugs f,fitted in notches gin the face-plate, as shown in Fig. 41. Moreover, thecap-plate may be dispensed with where, as in the case ofsewing-machine-table legs, safes, and other metallic articles, a socketcan be cast or drilled in the metallic article or an attachment to it totake the place of the cap-plate; hence in the use of the terms capplateor thrust-piece I mean to include all these forms.

In Figs. 6 and 7 the plate d, which takes theplaceof the cap-plate, mayhave the flanges it along its angular edges to lap upon the corner of asafe. The plate (1 may be secured to the safe by bolts 1', countersunkin the plate. The socket in the plate cl is elongated and the ball 0 isheld. therein by the faceplate a.

Some of the advantages of my invention are as follows: The parts of thesocket or frame may be struck up very readily from sheet metal in dies,or maybe equally as readily cast. The ball or sphere in motion can hitbut one end of the elongated opening in the face-plate at any one time,and then only at a single point of contact instead of a surface contact,as would be the case if the open ing in the face-plate were of the sameshape and substantially the same diameter as the ball. Again, thecap-plate, being flat at top and its ends upright, provides only pointsof contact for the ball instead of surfaces,which latter would be themode of contact were the cap-plate of substantially the shape of theball; and, still further, the ballbeing left free to move lengthwise ofthe opening-that is to say, to roll in its frame or socket-the points ofcontact are changed and the liability of the ball wearing away unevenlyis overcome.

Moreover, by reason of the fact that the ball has simply points ofcontact with its socket or frame, and, further, by reason of the factthat it has a rolling instead of simply a rotary motion in its socket orframe, the friction of the ball in action is very largely reduced, andhence the caster is one that will operate very freely.

Very obviously my caster is applicable to furniture, trunks, and allother classes of manufactures requiring or to which may be appliedcasters.

WVhat I claim is 1. A caster for furniture and other articles consistingof a ball, and aface-plate provided with an elongated opening in whichthe ball may roll, combined with a thrust-piece for receiving the thrustor impact of the ball, the ball coming in contact therewith at pointsonly as distinguished from surface contact, substantially as described.

2. A caster for furniture and other articles, consisting of aball, aface-plate provided with an elongated opening in which the ball mayroll, and a cap-plate constructed of fiatmetal bent substantially intoan inverted-U shape and applied to the face-plate for receiving thethrust of the ball, the ball having simply points of contact with thecap-plate and with the face-plate Whenever it comes in contact with thelatter, substantially as described.

In testimony whereof I have hereunto set my hand this 25th day ofNovember, A. D.

HARTWELL A. DALRYMPLE. WVitnesses:

WILL AM H. DAVIS, FRED M. BUTLER.

